Reveal from FAB or other UI Element

Reveal.java

private void reveal(View sourceView, int colorRes) {
        groupOverlay =
                (ViewGroupOverlay) getWindow().getDecorView().getOverlay();

        final Rect displayRect = new Rect();
        mMainDisplay.getGlobalVisibleRect(displayRect);

        // Make reveal cover the display and status bar.
        revealView = new View(this);
        revealView.setBottom(displayRect.bottom);
        revealView.setLeft(displayRect.left);
        revealView.setRight(displayRect.right);
        revealView.setBackgroundColor(getResources().getColor(colorRes));
        groupOverlay.add(revealView);

        final int[] clearLocation = new int[2];
        sourceView.getLocationInWindow(clearLocation);
        clearLocation[0] += sourceView.getWidth() / 2;
        clearLocation[1] += sourceView.getHeight() / 2;

        final int revealCenterX = clearLocation[0] - revealView.getLeft();
        final int revealCenterY = clearLocation[1] - revealView.getTop();

        final double x1_2 = Math.pow(revealView.getLeft() - revealCenterX, 2);
        final double x2_2 = Math.pow(revealView.getRight() - revealCenterX, 2);
        final double y_2 = Math.pow(revealView.getTop() - revealCenterY, 2);
        final float revealRadius = (float) Math.max(Math.sqrt(x1_2 + y_2), Math.sqrt(x2_2 + y_2));

        final Animator revealAnimator =
                ViewAnimationUtils.createCircularReveal(revealView,
                        revealCenterX, revealCenterY, 0.0f, revealRadius);
        revealAnimator.setDuration(
                getResources().getInteger(android.R.integer.config_longAnimTime));

        final AnimatorSet animatorSet = new AnimatorSet();
        animatorSet.play(revealAnimator);
        animatorSet.setInterpolator(new AccelerateDecelerateInterpolator());
        animatorSet.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animator) {
                startActivity(
                        new Intent(MainActivity.this, TweetActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
                );
            }
        });

        animatorSet.start();
    }